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142 changes: 69 additions & 73 deletions 12_Day_Regular_expressions/12_day_regular_expressions.md
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Expand Up @@ -95,22 +95,22 @@ let regEx = new RegExp('love','gi')
Declaring regular expression with global flag and case insensitive flag.

```js
let regEx= /love/gi
let regEx = /love/gi
```

The above regular expression is the same as the one which we created with RegExp constructor

```js
let regEx= new RegExp('love','gi')
let regEx = new RegExp('love','gi')
```

### RegExpp Object Methods
### RegExp Object Methods

Let us see some of RegExp methods

#### Testing for a match

*test()*:Tests for a match in a string. It returns true or false.
*test()*: Tests for a match in a string. It returns true or false.

```js
const str = 'I love JavaScript'
Expand All @@ -125,7 +125,7 @@ true

#### Array containing all of the match

*match()*:Returns an array containing all of the matches, including capturing groups, or null if no match is found.
*match()*: Returns an array containing all of the matches, including capturing groups, or null if no match is found.
If we do not use a global flag, match() returns an array containing the pattern, index, input and group.

```js
Expand Down Expand Up @@ -303,26 +303,18 @@ Using the square bracket and or operator , we manage to extract Apple, apple, Ba
```js
const pattern = /\d/g // d is a special character which means digits
const txt = 'This regular expression example was made in January 12, 2020.'
const matches = txt. match(pattern)
const matches = txt.match(pattern)

console.log(matches) // ["1", "2", "2", "0", "2", "0"], this is not what we want
```

```js
const pattern = /\d+/g // d is a special character which means digits
const txt = 'This regular expression example was made in January 12, 2020.'
const matches = txt. match(pattern)

console.log(matches) // ["12", "2020"], this is not what we want
```

### One or more times(+)

```js
const pattern = /\d+/g // d is a special character which means digits
const txt = 'This regular expression example was made in January 12, 2020.'
const matches = txt. match(pattern)
console.log(matches) // ["12", "2020"], this is not what we want
const matches = txt.match(pattern)
console.log(matches) // ["12", "2020"], this is what we want
```

### Period(.)
Expand Down Expand Up @@ -373,10 +365,10 @@ console.log(matches) // ["e-mail", "email", "Email", "E-mail"]

### Quantifier in RegExp

We can specify the length of the substring we look for in a text, using a curly bracket. Let us see, how ot use RegExp quantifiers. Imagine, we are interested in substring that their length are 4 characters
We can specify the length of the substring we look for in a text, using a curly bracket. Let us see, how to use RegExp quantifiers. Imagine, we are interested in substring that their length are 4 characters

```js
const txt = 'This regular expression example was made in December 6, 2019.'
const txt = 'This regular expression example was made in December 6, 2019.'
const pattern = /\\b\w{4}\b/g // exactly four character words
const matches = txt.match(pattern)
console.log(matches) //['This', 'made', '2019']
Expand Down Expand Up @@ -442,94 +434,98 @@ console.log(result) // true
### Exercises: Level 1

1. Calculate the total annual income of the person from the following text. ‘He earns 4000 euro from salary per month, 10000 euro annual bonus, 5500 euro online courses per month.’
1. The position of some particles on the horizontal x-axis -12, -4, -3 and -1 in the negative direction, 0 at origin, 4 and 8 in the positive direction. Extract these numbers and find the distance between the two furthest particles.
2. The position of some particles on the horizontal x-axis -12, -4, -3 and -1 in the negative direction, 0 at origin, 4 and 8 in the positive direction. Extract these numbers and find the distance between the two furthest particles.

```js
points = ['-1', '2', '-4', '-3', '-1', '0', '4', '8']
sortedPoints = [-4, -3, -1, -1, 0, 2, 4, 8]
distance = 12
```
```js
points = ['-1', '2', '-4', '-3', '-1', '0', '4', '8']
sortedPoints = [-4, -3, -1, -1, 0, 2, 4, 8]
distance = 12
```

1. Write a pattern which identify if a string is a valid JavaScript variable
3. Write a pattern which identify if a string is a valid JavaScript variable

```sh
is_valid_variable('first_name') # True
is_valid_variable('first-name') # False
is_valid_variable('1first_name') # False
is_valid_variable('firstname') # True
```js
console.log(is_valid_variable('first_name')) // True
console.log(is_valid_variable('first-name')) // False
console.log(is_valid_variable('1first_name')) // False
console.log(is_valid_variable('firstname')) // True
```

### Exercises: Level 2

1. Write a function called *tenMostFrequentWords* which get the ten most frequent word from a string?
1. Write a function called *tenMostFrequentWords* which get the ten most frequent word from a string

```js
paragraph = `I love teaching. If you do not love teaching what else can you love. I love Python if you do not love something which can give you all the capabilities to develop an application what else can you love.`
console.log(tenMostFrequentWords(paragraph))
paragraph = `I love teaching. If you do not love teaching what else can you love. I love Python if you do not love something which can give you all the capabilities to develop an application what else can you love.`
console.log(tenMostFrequentWords(paragraph))
```

```sh
[
{word:'love', count:6},
{word:'you', count:5},
{word:'can', count:3},
{word:'what', count:2},
{word:'teaching', count:2},
{word:'not', count:2},
{word:'else', count:2},
{word:'do', count:2},
{word:'I', count:2},
{word:'which', count:1},
{word:'to', count:1},
{word:'the', count:1},
{word:'something', count:1},
{word:'if', count:1},
{word:'give', count:1},
{word:'develop',count:1},
{word:'capabilities',count:1},
{word:'application', count:1},
{word:'an',count:1},
{word:'all',count:1},
{word:'Python',count:1},
{word:'If',count:1}]
[
{word:'love', count:6},
{word:'you', count:5},
{word:'can', count:3},
{word:'what', count:2},
{word:'teaching', count:2},
{word:'not', count:2},
{word:'else', count:2},
{word:'do', count:2},
{word:'I', count:2},
{word:'which', count:1},
{word:'to', count:1},
{word:'the', count:1},
{word:'something', count:1},
{word:'if', count:1},
{word:'give', count:1},
{word:'develop',count:1},
{word:'capabilities',count:1},
{word:'application', count:1},
{word:'an',count:1},
{word:'all',count:1},
{word:'Python',count:1},
{word:'If',count:1}
]
```

```js
console.log(tenMostFrequentWords(paragraph, 10))
```

```sh
[{word:'love', count:6},
{word:'you', count:5},
{word:'can', count:3},
{word:'what', count:2},
{word:'teaching', count:2},
{word:'not', count:2},
{word:'else', count:2},
{word:'do', count:2},
{word:'I', count:2},
{word:'which', count:1}
[
{word:'love', count:6},
{word:'you', count:5},
{word:'can', count:3},
{word:'what', count:2},
{word:'teaching', count:2},
{word:'not', count:2},
{word:'else', count:2},
{word:'do', count:2},
{word:'I', count:2},
{word:'which', count:1}
]
```

### Exercises: Level 3

1. Writ a function which cleans text. Clean the following text. After cleaning, count three most frequent words in the string.
1. Write a function which cleans text. Clean the following text. After cleaning, count three most frequent words in the string.

```js
```js
sentence = `%I $am@% a %tea@cher%, &and& I lo%#ve %tea@ching%;. There $is nothing; &as& mo@re rewarding as educa@ting &and& @emp%o@wering peo@ple. ;I found tea@ching m%o@re interesting tha@n any other %jo@bs. %Do@es thi%s mo@tivate yo@u to be a tea@cher!?`
console.log(cleanText(sentence))
```
```

```sh
I am a teacher and I love teaching There is nothing as more rewarding as educating and empowering people I found teaching more interesting than any other jobs Does this motivate you to be a teacher
```js
// Output
'I am a teacher and I love teaching There is nothing as more rewarding as educating and empowering people I found teaching more interesting than any other jobs Does this motivate you to be a teacher'
```

2. Write a function which find the most frequent words. After cleaning, count three most frequent words in the string.

```js
```js
console.log(mostFrequentWords(cleanedText))
[{word:'I', count:3}, {word:'teaching', count:2}, {word:'teacher', count:2}]
```
```

🎉 CONGRATULATIONS ! 🎉

Expand Down